Oil (i.e. non-aqueous) based fluids have long been known in the art for use in metalworking process (i.e. processes for mechanically shaping and working metals). Such fluids have exhibited good lubricating and cooling functions which reduce friction and dissipate heat in a metalworking process, This reduction of friction and dissipation of heat promotes long tool life, increases production and allows the attainment of high quality finished metal products. Many of the oil based metalworking fluids contain sulfurized oils to achieve effective friction reduction in the metalworking process. These sulfurized oils often have a high sulfur content and cause odor problems in metalworking operations, especially when sufficient heat is generated in the metalworking process. Notwithstanding the effectiveness of many oil based metalworking fluids such fluids exhibit, in addition to odor problems, disposal problems, health problems from vapors, safety problems, material availability problems and costs which have lead to the increased demand for and use of aqueous based metalworking fluids. Aqueous based metalworking fluids have been found to have fewer disposal, health, safety and availability problems than oil based metalworking fluids. Aqueous based metalworking fluids have low fire hazard, often easier disposal and many times lower cost characteristics compared to oil based metalworking fluids. In spite of these advantages aqueous based metalworking fluids have often exhibited lower performance (e.g. lower friction reduction) than oil based metalworking fluids. This lower performance has resulted often in a reduction in productivity and tool life. In metal grinding operations such lower performance is shown in greater wheel wear, lower G-ratios, increased frequency of wheel dressing, lower output and poorer finish on the parts.
Metalworking operations mechanically shape and work metallic workpieces by cutting and non-cutting processes. The cutting processes include, for example, drilling, grinding, milling, tapping, turning and broaching. Non-cutting processes include, for example, rolling, drawing, extrusion, drawing and ironing, punching, stamping and spinning processes.
There has been and continues to be the need for improving the performance of aqueous based metalworking fluids. In view of the safety, environmental and economic advantages of aqueous based metalworking fluids the art has thus continuously sought the improvement of the performance of such fluids.
It is therefore an object of this invention to provide an aqueous machining fluid composition for improving mechanical shaping and working processes on metallic and solid non-metallic workpieces. Another object of this invention is to provide an aqueous machining fluid composition overcoming disadvantages of prior art aqueous metalworking fluids. A still further object of this invention is to provide an aqueous machining fluid composition which avoids disadvantages of prior art non-aqueous oil based metalworking fluids.